cpu/stm32_common: add missing doxygen group definition
cpu/stm32_common: add missing doxygen group definition

avmelnikoff/RIOT,cladmi/RIOT,cladmi/RIOT,kerneltask/RIOT,A-Paul/RIOT,gebart/RIOT,josephnoir/RIOT,rfuentess/RIOT,beurdouche/RIOT,neiljay/RIOT,josephnoir/RIOT,avmelnikoff/RIOT,RIOT-OS/RIOT,adjih/RIOT,biboc/RIOT,kYc0o/RIOT,lazytech-org/RIOT,josephnoir/RIOT,immesys/RiSyn,cladmi/RIOT,basilfx/RIOT,authmillenon/RIOT,kaspar030/RIOT,smlng/RIOT,ant9000/RIOT,gebart/RIOT,hamilton-mote/RIOT-OS,kbumsik/RIOT,LudwigOrtmann/RIOT,RIOT-OS/RIOT,smlng/RIOT,OTAkeys/RIOT,beurdouche/RIOT,mtausig/RIOT,cladmi/RIOT,toonst/RIOT,biboc/RIOT,adrianghc/RIOT,plushvoxel/RIOT,authmillenon/RIOT,x3ro/RIOT,lazytech-org/RIOT,ks156/RIOT,kbumsik/RIOT,yogo1212/RIOT,RIOT-OS/RIOT,roberthartung/RIOT,mfrey/RIOT,x3ro/RIOT,Josar/RIOT,jasonatran/RIOT,neiljay/RIOT,aeneby/RIOT,kerneltask/RIOT,jasonatran/RIOT,OTAkeys/RIOT,lazytech-org/RIOT,BytesGalore/RIOT,hamilton-mote/RIOT-OS,gebart/RIOT,BytesGalore/RIOT,x3ro/RIOT,yogo1212/RIOT,biboc/RIOT,kbumsik/RIOT,ant9000/RIOT,roberthartung/RIOT,immesys/RiSyn,OlegHahm/RIOT,miri64/RIOT,LudwigKnuepfer/RIOT,avmelnikoff/RIOT,LudwigOrtmann/RIOT,A-Paul/RIOT,RIOT-OS/RIOT,OlegHahm/RIOT,OlegHahm/RIOT,LudwigOrtmann/RIOT,kaspar030/RIOT,Josar/RIOT,kYc0o/RIOT,RIOT-OS/RIOT,hamilton-mote/RIOT-OS,OlegHahm/RIOT,adrianghc/RIOT,toonst/RIOT,mtausig/RIOT,adjih/RIOT,aeneby/RIOT,biboc/RIOT,toonst/RIOT,OTAkeys/RIOT,Josar/RIOT,kYc0o/RIOT,kYc0o/RIOT,cladmi/RIOT,adjih/RIOT,yogo1212/RIOT,kerneltask/RIOT,Josar/RIOT,jasonatran/RIOT,neiljay/RIOT,roberthartung/RIOT,biboc/RIOT,LudwigKnuepfer/RIOT,yogo1212/RIOT,plushvoxel/RIOT,ant9000/RIOT,neiljay/RIOT,x3ro/RIOT,rfuentess/RIOT,ks156/RIOT,immesys/RiSyn,aeneby/RIOT,avmelnikoff/RIOT,miri64/RIOT,ant9000/RIOT,authmillenon/RIOT,neiljay/RIOT,authmillenon/RIOT,aeneby/RIOT,adrianghc/RIOT,LudwigOrtmann/RIOT,OlegHahm/RIOT,gebart/RIOT,kaspar030/RIOT,immesys/RiSyn,adjih/RIOT,smlng/RIOT,LudwigKnuepfer/RIOT,A-Paul/RIOT,adrianghc/RIOT,plushvoxel/RIOT,OTAkeys/RIOT,gebart/RIOT,basilfx/RIOT,josephnoir/RIOT,mfrey/RIOT,yogo1212/RIOT,authmillenon/RIOT,authmillenon/RIOT,jasonatran/RIOT,hamilton-mote/RIOT-OS,mtausig/RIOT,miri64/RIOT,ks156/RIOT,rfuentess/RIOT,rfuentess/RIOT,BytesGalore/RIOT,kerneltask/RIOT,kaspar030/RIOT,toonst/RIOT,josephnoir/RIOT,adjih/RIOT,mtausig/RIOT,mtausig/RIOT,rfuentess/RIOT,mfrey/RIOT,beurdouche/RIOT,LudwigOrtmann/RIOT,jasonatran/RIOT,kaspar030/RIOT,smlng/RIOT,basilfx/RIOT,plushvoxel/RIOT,beurdouche/RIOT,beurdouche/RIOT,plushvoxel/RIOT,lazytech-org/RIOT,roberthartung/RIOT,aeneby/RIOT,BytesGalore/RIOT,avmelnikoff/RIOT,LudwigKnuepfer/RIOT,immesys/RiSyn,basilfx/RIOT,smlng/RIOT,immesys/RiSyn,miri64/RIOT,A-Paul/RIOT,yogo1212/RIOT,x3ro/RIOT,A-Paul/RIOT,LudwigKnuepfer/RIOT,mfrey/RIOT,roberthartung/RIOT,OTAkeys/RIOT,kbumsik/RIOT,ks156/RIOT,LudwigOrtmann/RIOT,ant9000/RIOT,hamilton-mote/RIOT-OS,kYc0o/RIOT,BytesGalore/RIOT,Josar/RIOT,lazytech-org/RIOT,toonst/RIOT,adrianghc/RIOT,basilfx/RIOT,kerneltask/RIOT,kbumsik/RIOT,miri64/RIOT,mfrey/RIOT,ks156/RIOT